Specifications: With simple structure, after blowing out the pipeline, you only need to screw the plug into all the return and drain ports. Using winterizing plugs to protect your pool against the harsh winter season. The swimming pool winter expansion plug is made of durable rubber material which can serve you for a long time. Item Name: Rubber Plug Material: Rubber Features: Winterizing, Swimming Pool Supplies, Protective Size: Upper Diameter: 6.3cm/2.48"(Approx.) Lower Diameter: 5.3cm/2.09"(Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Rubber Plug